I could some insight on this subject. Sorry, if this the wrong forum for this subject. I've already read "The Master Handbook on Acoustics" 3rd ed. and the author mentioned VERY briefly about the subject and mentioned this product. He never did tell us how to find flutter echoes unless I missed it somehow. This product is pretty narrow in width. What would they sound like and how would one go about finding the correct spot to apply the treatment in a room? Do they just cover the whole walls with the above-mentioned product? Thanks in advance for any/all help.